#1 key的判断  key in dict 返回true或false
#2 字典元素的删除  del dict ['张三']
#4 字典元素的清空  dict.clear()
#3 字典元素的新增  dict ['张三']=99
#4 字典元素的修改  dict ['张三']=100 

scores={'张三':22,'李四':33}
print('张三' in scores)
print(scores)
del scores['张三']#删
print(scores)
scores ['王麻子']=99 #增
print(scores)
scores ['王麻子']=100 #改
print(scores)
scores.clear() #清空
print(scores)
